Constant torque winding means for slitting machines



1950 s. a AMOS ETAL ,533,307

CONSTANT TORQUE WINDING MEANS FOR SLITTING MACHINES Filed July 16. 1948 mv vron. sr 51v EARL AMOS and 321m GREELMAN JEFFREXM.

BY wafa.

ATTORNEY Patented Dec. 12, 1950 2,533,307 I CONSTANT TORQUE WINDING MEANS FOR SLITTING MACHINES Stephen Earl Amos, W Be! and Dougilmington, las Creelman Jeilrey, Jr Bic signors to E. I. du Pont de Nemonrs & Company, Wilmington, Del.,'a corporation of Delaware Application July 10, 104:, Serial No. 39.114

This invention relates to web winding and more particularly to improvements in apparatus for winding slit film, paper and the like as it comes from a-slitting machine.

In the manufacture of narrow webs of nonfibrous peliicular material such as regenerated cellulose film and'of fibrous peilicular material such as paper, it is customary to carry a wide web of pelllcular material past aligned slitting knives of a slitting machine and to wind the resulting narrower widths of web material on a suitable mandrel to form a package.

A windup arrangement currently used commercially in the packaging of slit film is as follows; a keyed spacing sleeve is first slipped over the surface of, and keyed to a driven wind-up mandrel or shaft. Then a paper core is slipped on the mandrel next tothe spacer, followed by another keyed spaclng sleeve, a second core, another sleeve etc. When the mandrel has been filled with spacing sleeves and cores, a spring-pressed abutment applies end pressure to the assemblage ..-to regulate the pressure, and therefore the friction, between the ends of the paper cores and the sleeves. The sleeves, being keyed to the mandrel, turn at mandrel speed while only the friction 'makes the cores turn. which produces the wind-up tension. The chief drawback to this type of a wind-up is that as the weight of the slit roll increases, the component of torque produced by the friction between the mandrel and the.

core increases since the core rests directly on the mandrel. and a poor winding pattern is obtained. It has been determined that the Optimum winding pattern for slit rolls results when the winding is accomplished under substantially constant torque conditions. Substantially constant torque winding minimizes blush and distortion of the web or film at the of! gauge locations, prevents excessive buckling or starring" of the web or film next to the core, and when the roll is subjected to freezing temperatures and allowed to return to normal temperature it exhibits good resistance to telescoping. Moreover, where rolls of unequal width or weight (due to difference in diameter) are wound upon the same mandrel, it is very difllcult to wind the wider or heavier roll with satisfactory film tension without imposing too great a strain on the narrower film.

An object of this invention therefore is to provide a wind-up device for slitting machines wherein the turning force on the roll of slit web is of substantially constant torque at all times 3 Claims. (CI. 24:45)

Another object is to provide wind-up means for slitting machines which will give unifm'mly luspacersandpapercoreateachendofthecole on the conventional wind-up mandrel. The assembly is constructed to support the paper case out of contact with the mandrel at all than, the collar at each end of the core together with the ll core forming, in eiiect, a wind-up bobbin. Be-

ferentlallyandpassing drilled in the friction ring, outerballrace.andtheedgingdisc. Theinner sleeves'ltobekeyedtheretoindrivingrehtlanship. Theinner diameters ofthefristionring l.theouterballracel,andtheedgingdisel areslightlygreaterthanthediameterotthemanlipservestosupportthecoreloutofcontset withmandreli.

Preferably, bolls I also some p ckasecoreandpreventroteflmoffliem 3 the mandrel against an end abutment thereon, thgs mugging, p the keyway ot'the mandrel, then friction ring-edging disc assembly described hereinabove is slipped over the surface of the mandrel against the spacen next a paper core goes on and finally another ball bearing friction ring-edging disc'assembly facing in the opposite direction so that the core is sup:

inner I construction (not shown) applies end pressure- 159 3 the assemblage. Thus, the torque drivin t disc assembly is produced principally by the keyed spacers contacting the friction rings and to only a-uslisht neareenby the \disc tassembly contacting thermandrel-rthrough ,athe ballbearings: The: 5

component zotttorque caused by the spacing collarsiis-inearlymonstanta; whet-ball bearing minimizettheeil'echof the increasing weight off a slit. dm'ingthe-minding operation, since they holduthecorejawayi'trom; the: mandrel and'carry the :weightionithe a e flheedging dlsctisusually made 1 new amusimpaled" on the sham qo In the table it is increases, the torqii rises'103%, while with the ball bearing friction ring-edging disc it actually falls 10%. This constttntes a tremendous improvement and can be considered essentially constant torque.

In the foregoing preferred embodiment ball oil bearing, etc. could be employed with like eflect.

means other than the prong means for enandsuch means are within the elation.

diflerent embodiments can obj v thout departing from the spirit pe bf'thi'sin'vention it is to be understood .thattthesinvention is in no wise limited save as set forth in the appended claims.

1. In a wind-up devic" for a slitting machine fl s 'e' s s y- -w ndf-. r a core fitted o'ver afpoi'ti'on ofth'e lengthoffsa 1 mandrel" upon which 'slit' pellicula rf material is? wound and a spacing sleeve fltted-iover saidman drel'and'fixe'd wsaid man rrrbribtaupntn rcwithgan 'end oi, said-spacingsleeve being n relationship: with an" tain'ed' in frictional dri't' I I end of said corewhereb rotation of 'saidmandi'el ana sam spacing sleeve imparts rotation; to said than sthe :maximumw diameter of; :then slit :rollzxi cor'exthe improvement whi'h compr ses annular This:isi*particular-1y ;-;necesaars'when-filmswith mean'sinterposed between s q'spscmgsleev'esqc slippery urtace iareabeing-slitinorder to assure' as said core, saidannular- -means beingsup'ported aauniIormLvswounde-upmedge.. *II' thew material.

the sameidiameieriasztheri'riction ring; I31. Y

scribeducommercialjprioruart arrangement here- 1: inafterjetermed iiold .methodf't'is' shownin the table. Increase in roll radius, of course, indicates* disc 'flkedly attached" increaselimizoll .aweight, which: increases 'asCthe square to! thesradiusia rolls wer'c formedgof i cellulose acetate fllm- 0.0008? wound at BallBearing "Frlctl a e e I 8 [ii r l rotatable s td ns ma ri frictionless? bearin s anc beingamrmeg n;-

scructed-tosunscreens-screen pr; contact'wlth'f ia w hi me saidjman drel} and in a e to said annular me n i y' ngage the spacin eeve n enjsn m r' an i mee n flcsl y eans associated'with alignedwith sai ring;

said ring"an'ddisc' mr s'upporting'said; coreoutjoff j I contact withssicman rel and mecn oh am disc I' for "positively -engaging sgidfcorefi'or rotational.

movement saidfrlng an'd' 'disc' being mounted on;

said mandrel by -mes s ar frictionlessflbearingsij a. The im royement of chum 2 wherein fthe tric s s' e afhfll eii il a sts n 1 T an 'oiiter race with" the ring and the an! nular disc and l an inner-"race" mounted on said ring and disc' but rotatable with respect 1' band disc and outer race and adapted to Q- s'rEP" ms m a I messes sea;-

Certificate of Correction I Patent No. 25533307 I December 12, 1950 STEPHEN EARL AMOS ET AL.

It is herebg'e certified that error appears in the printed specification of the above num red patent requiring correction as follows:

Column 3, line 57, in the table, first column thereof, for 1 read 1 and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 6th day of March, A. D. 1951;

THOMAS F. MURPHY,

Assistant Commissioner of Patents. 

